It is customary to pour a molten steel melt from its steel-making furnace into a ladle which is then carried to a casting location.
To keep the melt hot while it is in the ladle, possibly permitting final treatment of the melt, the ladle can be provided with a consumable arcing electrode positioned on the ladle's vertical axis with the ladle having a melt electrode in its bottom portion and normally symetrically disposed with respect to the ladle's axis and the arcing electrode. The melt electrode can be in the bottom of the furnace in alignment with the arcing electrode or more preferably in the form of an annulus extending around the ladle's wall closely above the ladle's bottom and concentrically around the ladle's axis symetrically with respect to the arcing electrode.
The ladle is then a ladle furnace. It is provided with DC arc heating by connecting DC power to the electrodes, with a DC power flow through the melt. Normally the arcing electrode is operated cathodically with the melt electrode providing the anode. When the melt electrode is in the form of the annulus mentioned, the current flow through the melt is substantially vertical but spreads symetrically from the foot point of the arc on the melt down to the annular melt connection in the lower part of the ladle wall, close to the ladle's bottom. When the melt connection is centrally in the bottom of the ladle the current flow is vertically between that melt electrode and the foot point of the arc.
The magnetic forces induced in the melt by the above current flow cause stirring of the melt in a generally vertical direction, the melt moving downwardly along the ladle's axis below the arc, upwardly along the wall of the ladle and inwardly towards the ladle's axis and along the melt's surface area.